Exercising apparatus, to be useful, should allow the user to strengthen only those muscles necessary for a particular sport. For a swimming simulator, the rotation and body positioning during exercise should fully simulate the motions involved in swimming in water. Existing exercise devices include swim benches which permit some form of rotation of the body, however, independent rotation of the upper and lower body portions of the user is not provided by the prior art systems.
For example, U.S. Pat. No. 4,674,740 issued to Iams et al. on Jun. 23, 1987 discloses a swimming trainer which allows for a rocking motion of the body during execution of the stroke. The user's torso and hips in the Iam device lay on a common bench and the entire frame moves as one, causing the entire body to rock. A drawback to this design is that the lower body must rotate with the upper body.
Another related swimming machine uses two independent supports for the upper and lower body. In U.S. Pat. No. 5,158,513, issued to Reeves on Oct. 27, 1992, the user's body is supported in a generally horizontal position so the user can pull against hand paddles which activate a resistance mechanism. However, the support for the upper body which allows for chest rotation forces the chest out of line with the head because its center of rotation is below the body. A proper stroke technique requires that the body should rotate about a center axis which is approximately in line with the spine of the body.
In U.S. Pat. No. 5,354,251 to Sleamaker, a swimming machine that uses a bench support for the user's body is provided where the bench actually tilts from side to side. This allows for movement and rotation of the body from side to side in order for the user to lean into the stroke. However, this type of movement causes a user to weave from left and right while he/she progresses through the water. Thus, the swimmer would be traveling a greater distance because they would not be moving in a straight line.
Other exercising devices such as that of U.S. Pat. Nos. 4,830,363 and 3,791,646 are known, however, unlike the present invention, the prior art does not provide for the independent movement where the torso or upper body portion is permitted to rotate with a center of rotation that is located above the bench and approximately in line with most users' spines.